Ferber, Reed, 1970-
2008-02-10T04:19:28Z
2008-02-10T04:19:28Z
2001
0-493-35824-2
http://hdl.handle.net/1794/148
Adviser: Louis R. Osternig.
xix, 196 leaves
A print copy of this title is available through the UO Libraries under the call number: SCIENCE RD561 .F47 2001
The purpose of this study was to investigate the gait patterns in persons with chronic ACL deficiency (ACLD: n = 10) who subsequently undergo surgical repair, and to determine how these individuals respond to an unexpected forward perturbations (FP) compared to healthy controls (n = 10). An unexpected FP was applied using a moveable force plate imbedded in a walkway. During nonperturbed (NP) gait, ACLD subjects exhibited similar knee moment patterns compared to healthy adults but appeared to accommodate to ACLD through alterations of hip and ankle joint kinematic, kinetic, and muscle power patterns. Three months following surgery, these same subjects demonstrated a significantly different knee moment pattern and were significantly more flexed at the knee and hip during NP gait. These data suggest that time since injury plays an important role in the adaptation of gait mechanics and must be considered when evaluating post-surgical ACL subjects. These data also suggest that ACL surgery significantly alters lower extremity gait patterns and that the re-establishment of pre-injury gait patterns takes longer than 3 months to occur. When healthy adults experienced an unexpected FP, the hip was favored in maintaining control of the upper body and in preventing collapse. In response to the same FP, ACLD subjects demonstrated a hip moment pattern similar to controls but a greater knee extensor moment. The increased knee moment pattern was more prevalent 3 months following surgery. These data suggest that ACLD and ACLR subjects rely more on knee extensor muscles for the prevention of collapse when reacting to an unexpected FP. Bilateral accommodations to ACL injury and surgery during NP and FP gait were also examined. During NP gait, healthy adults demonstrated asymmetrical hip moment and power patterns whereas ACLD and ACLR subjects exhibited symmetrical hip but asymmetrical knee mechanics. In response to the FP, healthy adults exhibited lower extremity joint symmetry but the ACLD and ACLR group exhibited asymmetrical knee moment and power patterns. These findings suggest that ACL injury and surgery result in bilateral joint accommodations and that when investigating ACL injured populations, bilateral control population data should be used in addition to non-injured limb data.
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University of Oregon
University of Oregon theses, Dept. of Exercise and Movement Science, Ph. D., 2001
Anterior cruciate ligament -- Wounds and injuries
Anterior cruciate ligament -- Surgery -- Patients -- Rehabilitation
Gait disorders
Gait in humans -- Physiological aspects
Knee -- Surgery -- Patients -- Rehabilitation
Gait perturbation response in anterior cruciate ligament deficiency and surgery
Thesis

Joshi, Aditi A.
2009-02-07T00:46:19Z
2009-02-07T00:46:19Z
2007-12
http://hdl.handle.net/1794/8452
x, 133 p. ; ill. (some col.) A print copy of this title is available through the UO Libraries under the call number: SCIENCE QP405 .J67 2007
Meditation has been defined as a "group of practices that self-regulate the body and mind, thereby affecting mental events by engaging a specific attentional set" (Cahn & Polich, 2006). We conducted a randomized, longitudinal trial to examine the effects of concentrative meditation training (40 min/day, 5 days/week for 8 weeks) on top-down, voluntary control of attention with a progressive muscle relaxation training group as a control.
To determine if training produced changes in attentional network efficiency we compared, pre- and post-training, mean validity effect scores (difference between invalid cue and center cue reaction time) in the contingent capture paradigm (Folk et al., 1992). The meditation group showed a trend towards improvement of top-down attention while the relaxation group did not.
Using EEG we assessed the changes in amplitudes of wavelets during periods of mind-wandering and meditation. Periods in which subjects were on- vs. off-focus during the meditation task were identified by asking subjects to make button presses whenever the mind wandered and also at probe tones, if they were off-focus. After training, the episodes of mind-wandering were significantly lower in the meditation group as compared to the relaxation group. Increased amplitudes of alpha and theta EEG frequencies in the occipital and right parietal areas were seen during the meditation task for the meditation but not the relaxation group as an effect of training. A baseline EEG trait effect of reduced mental activity was seen (meditation training: occipital and right parietal areas; relaxation training: only occipital areas).
Within a given meditation session, prior to training, alpha and theta activity was lower in on-focus conditions (occurring immediately after subjects discovered they were off-focus and returned to active focus on the breath/syllable) compared to meditative focus segments. After training, we found higher alpha amplitude in periods of meditative focus as compared to periods of mind wandering for both groups. However, the meditation group showed significantly higher theta amplitude than the relaxation group during the meditative state segments.
Adviser: Marjorie Woollacott
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, 2007, Ph.D.;
Electroencephalography
Meditation -- Physiological aspects -- Longitudinal studies
Attention -- Physiological aspects -- Longitudinal studies
Attention
Meditation
Mind-wandering
EEG
Effects of meditation training on attentional networks: A randomized controlled trial examining psychometric and electro-physiological (EEG) measures
Thesis

Lynn, Brenna Meaghan, 1977-
2009-01-14T01:23:38Z
2009-01-14T01:23:38Z
2008-06
http://hdl.handle.net/1794/8291
xiv, 233 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
In general, postexercise hypotension is characterized by a sustained increase in systemic vascular conductance that is not completely offset by ongoing increases in cardiac output. These hemodynamic changes are present immediately after a single bout of moderate-intensity dynamic exercise in healthy (sedentary and endurance exercise-trained) and hypertensive humans. The mechanisms underlying this postexercise hypotension are currently under investigation; however, the overall hemodynamic response may be altered in response to different factors related to sex, training status, and fluid regulation. The purpose of this dissertation was to investigate the contribution of endogenous hormones associated with the normal menstrual cycle and training status and sex on postexercise hemodynamics and to better understand how fluid replacement and heat-stress affect postexercise hemodynamics in a group of highly trained men. In Chapter IV, the contribution of the menstrual cycle and sex to postexercise hemodynamics was investigated. The results showed that postexercise hemodynamics are largely unaffected by sex and factors associated with the menstrual cycle. In Chapter V, the role of heat-stress and fluid replacement on the postexercise cardiac hemodynamics in a group of endurance exercise-trained men was investigated. These data suggest that fluid replacement and heat-stress mitigate the previously observed fall in cardiac output during exercise recovery in trained men. In Chapter VI, the study investigated the hemodynamic profile in well-hydrated sedentary and trained men and women during recovery from exercise. In contrast to previous research, the results showed a lack of variation in the postexercise hemodynamic response across categories of subjects as there was no evidence of a sex and training interaction. Thus, it appears that factors such as heat-stress and fluid replacement can alter postexercise hemodynamics in trained men; however, factors such as menstrual cycle, sex, and training status do not seem to influence the hemodynamic recovery profile. Yet substantial variation in the postexercise response across individuals remains unexplained.
This dissertation contains my previously published and my co-authored material.
Adviser: John R. Halliwill
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, Ph. D., 2008;
Physiology
Blood flow
Hormones
Hypotension
Dehydration
Postexercise
Postexercise hemodynamics: Interactions of sex, training status, and fluid regulation
Thesis

Chen, Chu Jui, 1981-
2008-10-15T18:06:57Z
2008-10-15T18:06:57Z
2008-06
http://hdl.handle.net/1794/7480
xi, 75 p. : ill. A print copy of this title is available through the UO Libraries under the call numbers: SCIENCE QP310.W3 C44 2008
This study was performed to evaluate the sensitivity of using electromyography
(EMG) and joint moment to quantify muscular challenges in elderly adults. Twenty elderly
and young adults walked on level ground and crossed an obstacle. Resultant hip, knee, and
ankle joint moments and EMG data from muscles of the dominant leg were analyzed.
Older adults demonstrated significantly greater normalized EMG (N-EMG) magnitudes
than young adults in most muscles. However, only hip abductor moment demonstrated
significant group differences. Stepping over a higher obstacle resulted in greater N-EMG
magnitudes in all muscles. Leading limb knee extensor moment was found to significantly
decrease with increasing obstacle height, while N-EMGs of knee joint muscles increased.
Our findings suggest that N-EMG, which can better account for co-activation of agonist
and antagonist muscles, might be a more sensitive parameter than the joint moment in
detecting age- and task-related differences.
Adviser: Li-Shan Chou
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University of Oregon
University of Oregon theses, Dept. of Human Physiology, M.S., 2008
Quantification of Muscular Demands in the Elderly: Electromyography vs. Joint Moments
Electromyography vs. Joint Moments
Thesis

Catena, Robert David, 1981-
2008-12-20T01:26:12Z
2008-12-20T01:26:12Z
2008-06
http://hdl.handle.net/1794/8151
xiii, 122 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
Currently the information on attention-balance control interactions following concussion is incomplete and not given particular consideration during clinical examinations of concussion. The purposes of this dissertation were to (1) test different gait paradigms for their sensitivity of identifying concussion symptoms and to (2) test how individual components of attention interact with gait performance. The long-term goal of this study is to establish more functional and succinct protocols for return-to-play decisions.
Grade II (AAN guidelines) concussed individuals were recruited to participate in testing at 2, 6, 14, and 28 days post-injury. Gait and components of attention were analyzed during each session through a number of different paradigms. Control subjects were matched by stature, age, and athletic participation.
The results indicate that the dynamic balance deficits following a concussion are immediately identified with an attention dividing gait task. Obstacle crossing identified more conservative adaptations 2 weeks after injury. A task combining the two did not clearly identify concussion deficits. Two components of attention showed promise as interacting with gait to cause balance deficits. The spatial orientation component showed an interaction with obstacle avoidance indicating that the same concussed individuals that had poor spatial orientation of attention also came closer to hitting the obstacle during crossings. An analysis of divided attention showed that concussed individuals performing poorly in one task also performed poorly in the other during a dual-task paradigm, but during any one particular trial there was a trade-off between task performances, which was not present in control individuals.
The findings of this dissertation point to the use of a divided attention task to distinguish concussed individuals from healthy individuals immediately after a possible injurious event. How several different components of attention interact with gait performance is identified. Finally, if a concussion has occurred, an obstacle crossing task might be suitable for a long-term analysis of full recovery of balance control. Ultimately, it is my hope that the information provided here will lead to functionally relevant and clinically executable tests of concussed individuals before they are placed in harm's way due purely to an incomplete diagnosis of their injuries.
Adviser: Li-Shan Chou
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, Ph.D., 2008;
Physiology
Physical therapy
Neurosciences
Obstacle crossing
Concussion
Gait
Attention
Attention and gait performance following a concussion
Thesis

Pellinger, Thomas Kent, 1970-
2009-04-23T22:11:32Z
2009-04-23T22:11:32Z
2008-09
http://hdl.handle.net/1794/9018
xvii, 168 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
An acute bout of moderate-intensity dynamic exercise results in a sustained rise in skeletal muscle blood flow from that of pre-exercise levels. This postexercise skeletal muscle hyperemia is mediated by two histamine receptors (subtypes, H 1 and H 2 ). Skeletal muscle glucose uptake is also enhanced, in an insulin-independent manner, following moderate-intensity dynamic exercise. The impact of skeletal muscle hyperemia on glucose regulation following exercise has yet to be examined. Therefore, the purpose of this dissertation was to determine if postexercise skeletal muscle hyperemia plays a substantial role in glucose regulation in humans. In Chapter III I tested my ability to block local H 1 - and H 2 -receptors located in the vastus lateralis muscle in humans. The results demonstrate that I was able to successfully block the increase in local blood flow evoked by compound 48-80 with the combination of the H 1 -receptor antagonist pyrilamine and the H 2 -receptor antagonist cimetidine, administered via skeletal muscle microdialysis. In Chapter IV I sought to determine the effect of local combined H 1 - and H 2 -receptor blockade, administered via skeletal muscle microdialysis, on postexercise interstitial glucose concentrations. My findings indicate postexercise delivery of glucose to the interstitial space of the previously active skeletal muscle is mediated, in part, by local H 1 - and H 2 -receptors. In Chapter V I examined the effect of oral administration of H 1 - and H 2 -receptor antagonists on glucose regulation following a postexercise oral glucose load. The results showed that the glycemic and insulin responses to postexercise oral glucose load were more sustained with H 1 - and H 2 -receptor blockade versus control, suggesting a histaminergic effect on postexercise glucose regulation.
Adviser: John Halliwill
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, Ph. D., 2008;
Physiology
Microdialysis
Histamine receptors
Blood flow
Postexercise hyperemia
Glucose
Impact of Postexercise Hyperemia on Glucose Regulation in Humans
Thesis

Silsupadol, Patima, 1975-
2009-02-16T23:41:35Z
2009-02-16T23:41:35Z
2008-09
http://hdl.handle.net/1794/8546
xiv, 96 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
Among older adults, an impaired ability to maintain balance while simultaneously performing cognitive tasks is a common occurrence. Because poor dual-task balance performance is associated with increased fall risk and a decline in cognitive function, interventions to improve dual-task balance performance are needed. Although traditional rehabilitation programs emphasizing training balance under single-task conditions are effective in improving single-task balance performance, it is not known whether single-task training generalizes to balance control under dual-task contexts. Moreover, the effectiveness of approaches to training balance under dual-task conditions is not known.
Thus, the purposes of this study were to determine whether elderly individuals with balance impairment can improve their balance performance under dual-task conditions; to investigate whether training balance under single-task conditions generalizes to balance control during dual-task contexts; and to evaluate the effect of instructional set on dual-task balance performance. Specifically, the efficiency of three different training strategies was examined in an effort to understand the mechanisms underlying training-related changes in dual-task balance performance. Twenty-three elderly adults with balance impairment were randomly assigned to 1 of 3 interventions: single-task balance training (ST); dual-task training with fixed-priority instruction (FP); and dual-task training with variable-priority instruction (VP). Clinical and laboratory measures were obtained at baseline and after training. In addition, selected clinical outcomes were repeated after the second week of training to examine interim balance change and at twelve weeks post training to test retention.
Results indicate that dual-task training was effective in improving balance under dual-task conditions in the elderly with balance impairment. Training balance under single-task conditions may not generalize to balance control during dual-task contexts. Explicit instruction regarding attentional focus was an important factor for improvement in dual-task performance. The VP instructional set offered advantages over the FP instructional set in terms of the degree of improvement, the rate of learning, and the retention of the dual-task training effect. The dual-task processing skills learned during training were not transferred to novel dual-task conditions. Lastly, the training benefits acquired during VP training could be the result of both automatization of the individual task and the development of task-coordination skills.
Adviser: Marjorie Woollacott
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, Ph. D., 2008;
Balance performance
Dual task training
Kinesiology
Physical therapy
Gerontology
Aging
Gait
Balance impairment
Older people
Effects of single- vs. dual-task training on balance performance under dual-task conditions in older adults with balance impairment: A randomized, controlled trial
Thesis

Amasay, Tal, 1968-
2009-02-14T00:47:19Z
2009-02-14T00:47:19Z
2008-09
http://hdl.handle.net/1794/8520
xvi, 128 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
There were two primary goals of this work. The first goal was to investigate humeral and scapular kinematics in a simulated workplace environment. The second goal was to validate a triaxial accelerometer (Virtual Corset) for the collection of humeral elevation exposure data in an occupational setting. To achieve the first goal, healthy subjects were asked to perform constrained and functional humeral elevation motions. Differences were observed in scapular kinematics. In addition, the variability between constrained arm elevation and functional overhead tasks was found to be similar. Therefore, to compare scapular kinematics in an occupational group (dental hygienists) a functional work related task was determined to be more appropriate. The dental hygienists performed teeth instrumentation on simulated patients' with both big and average chest girth in a simulated work environment. Dental hygienist's humeral elevation and scapular upward rotation angles were found to be higher while working on the big chest girth manikin. These differences may increase dental hygienists susceptibility for musculoskeletal disorders.
To achieve the second goal, an in-vitro comparison of angles measured with the Virtual Corset and an inclinometer was conducted under static conditions. Under dynamic conditions the Virtual Corset was compared to a potentiometer, in a pendulum setting. It was found that the Virtual Corset can accurately reconstruct elevation angles under static conditions, root mean square error less than 1[white square]. Under dynamic conditions, the error size was related to the angular velocity and acceleration, and the radius of rotation. To further investigate the Virtual Corset's ability to measure exposure parameters in-vivo the Virtual Corset was compare to a magnetic tracking device. To do so dental hygienists performed flossing tasks in a simulated work station. It was found that the Virtual Corset can be used to reconstruct elevation angles, with an acceptable angle error, and to identify exposure parameters in occupational settings similar to the one simulated in the present study.
This dissertation includes unpublished co-authored material.
Adviser: Andrew R. Karduna
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, Ph. D., 2008;
Physiology
Kinesiology
Occupational health
Arm motions
Dental hygienists
Musculoskeletal disorders
Occupational settings
Humeral elevation
Unconstrained humeral elevation exposure in occupational settings
Thesis

Simmons, Grant H., 1981-
2009-07-28T22:35:11Z
2009-07-28T22:35:11Z
2008-12
http://hdl.handle.net/1794/9495
xvii, 174 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
During acute altitude exposure, humans maintain higher skin temperature and lower core body temperature. However, the role of cutaneous vascular regulation in these thermoregulatory differences is unclear. Therefore, the purpose of these studies was to investigate the impact of altitude exposure on reflex control of skin blood flow and core temperature during cold exposure. In Chapter IV, the effects of hypoxia and hypocapnia on cutaneous vasoconstriction during mild cold exposure were investigated. We found that hypoxia stimulates cutaneous vasodilation in men whereas skin blood flow is unaltered in women. However, during whole body cooling skin blood flow is upward shifted in both sexes. The development of hypocapnia does not affect the vascular response to hypoxia in either sex, but reduces the magnitude of cutaneous vasoconstriction during cold exposure by 50% in women. In Chapter V, we studied the timecourse of α-adrenergic blockade by yohimbine in the cutaneous circulation and how the duration of cold exposure modulates cotransmitter-mediated vasoconstriction during cold stress. We found that yohimbine produces functional α-adrenergic blockade within 30 minutes of initial delivery and completely abolishes reflex cutaneous vasoconstriction during mild cold stress. This latter finding was surprising, and an additional protocol demonstrated that cotransmitter-mediated vasoconstriction only participates in the vascular response to cold stress when the exposure is more prolonged. In Chapter VI, the effects of hypoxia on cutaneous vasoconstrictor mechanisms and core cooling rate were tested during more prolonged and severe cold stress. In contrast to our findings during brief cold exposure, we showed that cutaneous vasoconstriction during prolonged cold stress is potentiated by hypoxia and abolishes hypoxic vasodilation. Moreover, increased cotransmitter-mediated vasoconstriction appears to account for this response. Hypoxia had no effect on core cooling rate during severe cold exposure. The selective potentiation of cotransmitter-mediated vasoconstriction observed during hypoxia in Chapter VI provided the basis for Chapter VII. This study was designed to test the effect of hypoxia on cutaneous vascular responsiveness to peripherally stimulated sympathetic vasoconstriction. The results demonstrated that α-adrenergic vasoconstrictor transduction is not affected by hypoxia, and that stimulation of adrenergic nerves with tyramine does not elicit cotransmitter-mediated vasoconstriction in skin.
Adviser: John R. Halliwill
en_US
University of Oregon
University of University of Oregon theses, Dept. of Human Physiology, Ph. D., 2008;
Vasodilation
Vasoconstrictor function
High altitude
Hypoxia
Physiology
Altitude, Influence of
Cutaneous vasodilation at simulated high altitude: Impacts on human thermoregulation and vasoconstrictor function
Thesis

Rolheiser, Tyler M., 1979-
2009-07-28T21:47:17Z
2009-07-28T21:47:17Z
2008-12
http://hdl.handle.net/1794/9494
xiii, 79 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
Traumatic brain injury has reached epidemic levels, and yet there are still large questions that need to be addressed regarding the underlying pathology and the related behavioral deficits. Adequately measuring the neurological sequelae associated with TBI in vivo requires the use of sophisticated imaging procedures, while quantifying behavioral deficits requires precise, sensitive testing procedures. The current analysis examined three potential biomarkers of TBI using MRI technology, as well as examining both fine motor and psychological function on a cohort of TBI participants at least 12 months post-injury. Ten participants with a history of traumatic brain injury and ten matched controls were recruited for the present analysis. All participants completed a series of four MRI scans, as well as a simple motor task and a cognitive test battery. Between group analysis revealed that the two groups could be differentiated based on two MRI measures (BOLD and FA), and on three behavioral measures (Fitts motor task, self-reported symptoms, and impulse control). A within group correlation analysis of the TBI participants did not reveal any significant relationship between the MRI data and behavioral deficits. A group-wide regression analysis, however, revealed that MRI markers of cortical damage significantly predicted deterioration in the Fitts motor task performance. The results of the current study suggest that the long-term effects of TBI are not confined to executive function, and that one's performance of a fine motor task has diagnostic potential.
Adviser: Paul van Donkelaar
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, Ph. D., 2008;
Cortical damage
Traumatic brain injury
Motor control
Neurosciences
Medical imaging
Physiology
Functional implications of cortical damage
Thesis

San Juan, Bernardo G., 1977-
2010-04-22T22:30:47Z
2010-04-22T22:30:47Z
2009-09
http://hdl.handle.net/1794/10325
xiii, 79 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
Subacromial impingement syndrome is the most common disorder of the shoulder. Abnormal superior translation of the humeral head is believed to be one of the major causes of this pathology. The overall purpose of this study was to better understand glenohumeral kinematics in normal healthy individuals using fluoroscopy to help comprehend the mechanism of shoulder impingement. This research was divided into three sections: a validation study to measure humeral head translation, a comparison between dynamic and static arm elevation and lastly, humeral head translation after a suprascapular nerve block.
In the first study, fluoroscopy was used to take images of human cadaver shoulders. Scapular orientation was manipulated in different positions while the humerus was at 90 degrees of elevation. Humeral head translation was measured using two methods and was compared to the known translation. Additionally, the accuracy of the contour registration method to measure 2-D scapular rotations was assessed.
For the second study, subjects elevated their dominant arm while fluoroscopic images were taken. An edge detection software was utilized to digitize points on both the humeral head and glenoid. Humeral head translation and scapular upward rotation were measured using a contour registration method with respect to the glenoid during arm elevation. Five different arm elevation angles were investigated to measure differences in humeral head translation between trials. There was no difference found between humeral head translation and scapular upward rotation between static and dynamic shoulder elevation.
For the third study, humeral head translation was measured before and after a suprascapular never block. The humeral head was superiorly located and the scapula was more upwardly rotated after the block. The differences were observed during mid range of motion. This result showed that there was a compensatory increase in both humeral head translation and scapular upward rotation due to the nerve block. These results suggest that increasing muscular strength and endurance of the supraspinatus and infraspinatus muscle could prevent any increased superior humeral head translation. This may be beneficial in preventing shoulder impingement or rotator cuff tear over time. This dissertation includes unpublished co-authored materials.
Committee in charge: Andrew Karduna, Chairperson, Human Physiology;
Li-Shan Chou, Member, Human Physiology;
Louis Osternig, Member, Human Physiology;
Stephen Frost, Outside Member, Anthropology
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, Ph. D., 2009;
Humeral head
Suprascapular nerve
Subacromial impingement
Shoulder disorder
Physical therapy
Measuring humeral head translation after suprascapular nerve block
Thesis

Sorenson, Eric A., 1980-
2010-08-05T23:27:05Z
2010-08-05T23:27:05Z
2009-12
http://hdl.handle.net/1794/10594
xiii, 89 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
Participation in athletics includes an inherent risk of becoming injured that is related to the nature of the games and activities of the players. Current literature reports that approximately seven million high school students participate in sports yearly in the United States and, during the 2005-2006 sport seasons, 1.4 million injuries were reported. Considering this high number of injuries, there is little doubt that definitive research into the determination of factors that might help predict the degree of injury risk associated with sport participation is warranted.
Despite common association of variables such as joint laxity, range of motion, strength and balance with injury, these traditional measures have not proven to be reliable predictors of vulnerability. Consequently, attempts have been made to identify practical methods that may better permit identification of individuals who show a high likelihood of injury during athletic competition.
This study examined one such system, the Functional Movement Screen (FMS), which utilizes measures of mobility and stability to permit its developers to assert that it can be used to practically and accurately identify vulnerable athletes. Critical data on inter-rater and intra-rater performance were first obtained on a team of athletic trainers to ensure that they could reliably execute the testing methods. Following confirmation of this fact, 112 high school basketball athletes were screened with the FMS and their injuries (non-contact neuromusculoskeletal tissue damage in school-sanctioned basketball) were tracked throughout an entire season. Data analysis to determine if a commonly-used FMS cutoff score of less than 14 out of 21 could identify vulnerable athletes revealed that this value was not significantly related to the likelihood of sustaining an injury. Furthermore, logistic regression revealed that none of the individual predictors (gender, FMS movements, and movement asymmetries) were significant predictors of injury susceptibility. The results indicate that, despite the fact that multiple evaluators and trials can be practically used to evaluate FMS scores in a large group of high school basketball athletes, the test does not appear to be a valid tool in assessing injury risk in this population during an entire season.
Committee in charge: Gary Klug, Chairperson, Human Physiology;
Paul van Donkelaar, Member, Human Physiology;
Andrew Lovering, Member, Human Physiology;
Roland Good, Outside Member, Special Education and Clinical Sciences
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, Ph. D., 2009;
Functional movement screen
High school athletes
Basketball players
Injury prevention
Sports injuries
Physical therapy
Kinesiology
Basketball injuries
Functional movement screen as a predictor of injury in high school basketball athletes
Thesis

Sorenson, Eric A., 1980-
2010-05-21T21:01:11Z
2010-05-21T21:01:11Z
2009-12
http://hdl.handle.net/1794/10375
xiii, 89 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
Participation in athletics includes an inherent risk of becoming injured that is related to the nature of the games and activities of the players. Current literature reports that approximately seven million high school students participate in sports yearly in the United States and, during the 2005-2006 sport seasons, 1.4 million injuries were reported. Considering this high number of injuries, there is little doubt that definitive research into the determination of factors that might help predict the degree of injury risk associated with sport participation is warranted.
Despite common association of variables such as joint laxity, range of motion, strength and balance with injury, these traditional measures have not proven to be reliable predictors of vulnerability. Consequently, attempts have been made to identify practical methods that may better permit identification of individuals who show a high likelihood of injury during athletic competition.
This study examined one such system, the Functional Movement Screen (FMS), which utilizes measures of mobility and stability to permit its developers to assert that it can be used to practically and accurately identify vulnerable athletes. Critical data on inter-rater and intra-rater performance were first obtained on a team of athletic trainers to ensure that they could reliably execute the testing methods. Following confirmation of this fact, 112 high school basketball athletes were screened with the FMS and their injuries (non-contact neuromusculoskeletal tissue damage in school-sanctioned basketball) were tracked throughout an entire season. Data analysis to determine if a commonly-used FMS cutoff score of less than 14 out of 21 could identify vulnerable athletes revealed that this value was not significantly related to the likelihood of sustaining an injury. Furthermore, logistic regression revealed that none of the individual predictors (gender, FMS movements, and movement asymmetries) were significant predictors of injury susceptibility. The results indicate that, despite the fact that multiple evaluators and trials can be practically used to evaluate FMS scores in a large group of high school basketball athletes, the test does not appear to be a valid tool in assessing injury risk in this population during an entire season.
Committee in charge: Gary Klug, Chairperson, Human Physiology;
Paul van Donkelaar, Member, Human Physiology;
Andrew Lovering, Member, Human Physiology;
Roland Good, Outside Member, Special Education and Clinical Sciences
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, Ph. D., 2009;
Functional movement screen
Athletes
Basketball players
Injury prevention
Sports injuries
Physical therapy
Kinesiology
High school athletes
High school basketball players
Functional movement screen as a predictor of injury in high school basketball athletes
Thesis

Boonyong, Sujitra, 1973-
2010-07-30T22:40:57Z
2010-07-30T22:40:57Z
2010-03
http://hdl.handle.net/1794/10564
xiii, 103 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
The purpose of this dissertation was (1) to investigate the effects of dual task conditions on the development of postural control during gait in typically developing children while walking and obstacle crossing, and (2) to investigate the attentional requirements of gait in children with cerebral palsy (CP). Forty younger and older typically developing (YTD and OTD) children and 10 children with CP performed a gait task with and without a concurrently auditory Stroop task. Gait and cognitive performance were measured.
In study 1, dual task interference with gait performance was found in YTD and OTD children, but not in healthy young adults (HYA). In general, gait performance decrements under dual task contexts were greater in YTD than OTD children, whereas cognitive performance decrements during dual tasking were not different between the two groups of children. Dual task interference was lowest in HYA and highest in YTD children when compared among groups. As the difficulty of the gait task was increased, dual task affects on cognitive performance were now found in YTD and OTD children, but not HYA.
In study 2, there were significant differences in dual task interference affecting gait performance in all groups of children. When performing the gait task with a concurrent auditory Stroop task, OTD children showed greater dual-task costs than children with CP for accuracy, but children with CP demonstrated greater dual-task costs than OTD and YTD children for medial Center of Mass-Ankle-joint-center inclination angle. This increased medio-lateral inclination angle in dual task situations has also been seen in older adults with balance deficits and may be associated with an increased risk for falls. YTD children showed dual-task costs in a slowing of gait velocity and stride time, a safer strategy than that used by children with CP. The lower cognitive performance during dual tasking for OTD children suggests that they allocate greater attention to maintain gait stability, whereas YTD children and children with CP do not. In addition, children with CP use a behavior that may increase their risk of falls in complex environments.
This dissertation includes unpublished co-authored material.
Committee in charge: Marjorie Woollacott, Chairperson, Human Physiology;
Paul van Donkelaar, Member, Human Physiology;
Li-Shan Chou, Member, Human Physiology;
Paul Dassonville, Outside Member, Psychology
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, Ph. D., 2010;
Postural control
Gait
Cerebral palsy
Dual task conditions
Neurosciences
Kinesiology
Gait disorders in children
Cerebral palsied children
Development of postural control during gait in typically developing children and children with cerebral palsy: The effects of dual task conditions
Thesis

Lorenzo, Santiago, 1978-
2010-07-21T21:38:11Z
2010-07-21T21:38:11Z
2010-03
http://hdl.handle.net/1794/10524
xvii, 245 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
There has been a lot of research investigating the effects of heat stress and exercise on the physiological adaptations to heat acclimation. It is well documented that heat acclimation improves heat tolerance and performance in a hot environment; however, some of the mechanisms of adaptation are not clear. Furthermore, the role of heat acclimation on exercise performance in cool environments is currently unknown. Therefore, in Chapter IV we aimed to determine the effects of heat acclimation on lactate threshold and maximal oxygen uptake (VO 2max ) in cool and hot conditions. We also sought to investigate the effects of heat acclimation on leg blood flow and oxygen delivery during a single-leg knee extensor exercise. We found that heat acclimation improved lactate threshold and VO 2max in cool and hot environments but did not alter the leg blood flow and oxygen delivery during the leg kicking exercise. In Chapter V we investigated the heat acclimation effects on performance during a 1-hour time trial in hot and cool environmental conditions and the potential mechanisms by which this occurs. A secondary objective was to study whether the pacing strategy was modified during the time trial post-heat acclimation. The results demonstrated that heat acclimation improved time trial performance in both thermal environments by approximately 7% but pacing strategy was not altered. The purpose of the studies in Chapter VI were twofold. First, we sought to investigate how heat acclimation affects the skin blood flow and sweating responses to pharmacological treatment with specific dosages of the muscarinic receptor agonist acetylcholine. Second, we examined the maximal skin blood flow responses to a period of heat acclimation by locally heating the forearm with a water spray device for 45 minutes and measured brachial artery blood flow via ultrasound. We found that heat acclimation increased sweat rate and skin blood flow responses to given concentrations of acetylcholine, suggesting a role for peripheral mechanisms. On the other hand, maximal skin blood flow remained unchanged after heat acclimation.
Committee in charge: Christopher Minson, Chairperson, Human Physiology;
John Halliwill, Member, Human Physiology;
Andrew Lovering, Member, Human Physiology;
Michael Sawka, Member, Not from U of 0;
Scott Frey, Outside Member, Psychology
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, Ph. D., 2010;
Heat acclimation
Exercise performance
Heat stress
Lactate threshold
Blood flow
Kinesiology
Physiology
Mechanisms of heat acclimation and exercise performance
Thesis

Becker, James N. M., 1979-
2010-06-18T00:59:38Z
2010-06-18T00:59:38Z
2010-03
http://hdl.handle.net/1794/10470
xiii, 143 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
This study evaluated the effects of two marker placement methods and two data
analysis methods on running gait analysis. Markers placed on the shoe heel counter were
compared with markers placed directly on the calcaneous and visible through heel
windows cut into the shoe. When analyzed using a traditional group design no
significant differences were found between marker conditions for rear foot eversion
excursion, percent stance at which peak eversion occurred, maximal instantaneous
eversion velocity, or maximal instantaneous vertical loading rate. Ankle frontal plane
variability was significantly different between conditions. When analyzed with a single
subject design some individuals demonstrated significant differences between conditions
while others did not. In some individuals the heel windows condition revealed previously
masked coupling parameters thought to be related to injury. The results of this study
suggest the heel windows method and single subject analysis should be used for a
longitudinal study of runners.
Committee in Charge:
Dr. Li-Shan Chou, Chair;
Dr. Louis Ostemig;
Dr. Stanley James
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, M.S., 2010;
Gait in humans
Effects of Two Marker Placement and Data Analysis Methods on Running Gait Analysis
Thesis

Saavedra, Sandra Lee, 1952-
2010-07-21T23:18:04Z
2010-07-21T23:18:04Z
2010-03
http://hdl.handle.net/1794/10530
xviii, 125p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
Trunk control is critical for all functional movement, yet little is known about the development of trunk stability. Previous research considered the trunk to be one rigid segment ignoring the complexity of multiple spinal segments. In healthy adults spinal control is so well orchestrated that this assumption is reasonable; however during development and more specifically in pathological conditions in which spinal control is immature or compromised, this assumption may prevent accurate analysis and/or treatment of the condition.
This dissertation investigates the mechanisms used by typical infants in gaining postural control of spinal segments for independent sitting. Infant data were compared to data from children with cerebral palsy (CP). The contribution of spinal segments was assessed by stabilizing the trunk in vertical alignment with four levels of support (axillae, mid-ribs, waist or hips). Documentation of postural sway of the head reflected the motor control available in the free segments of the spine. Kinematic data were collected bimonthly from 3 to 9 months of age in typically developing infants and 3-4 times over a 4 month time span in children with CP.
The infants' response to external support changed in a non-linear, stage-like fashion as they transitioned from immature to mature spinal control. Head stability emerged first at higher levels of trunk support and gradually progressed in a cephalocaudal pattern to lower levels of support. Emergence of functional sitting was associated with mastery of postural control in the lower lumbar and pelvic regions of the spine. The severity of CP was related to the level of spinal control achieved. Children with severe CP had control in the cervical or upper thoracic spine while those with moderate CP had control into the mid to lower thoracic spine. In addition, behavioral patterns seen in children with CP were consistent with developmental stages seen in typical infants during acquisition of vertical alignment. These findings challenge the existing clinical practice of evaluating and treating the trunk as a single segment, offer intermediate measures of progression of spinal control and propose that a more specific approach may create the foundation for improved motor outcomes in pathological populations.
Committee in charge: Marjorie Woollacott, Chairperson, Human Physiology;
Paul van Donkelaar, Member, Human Physiology;
Andrew Karduna, Member, Human Physiology;
Shawn Lockery, Outside Member, Biology
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, Ph. D., 2010;
Spinal segments
Posture
Cerebral palsy
Head control
Physical therapy
Kinesiology
Physiology
Contribution of spinal segments to control of posture during typical and atypical development
Thesis

LaRoux, Charlene I., 1979-
2011-04-09T00:30:06Z
2011-04-09T00:30:06Z
2010-12
http://hdl.handle.net/1794/11063
xii, 98 p. : ill. (some col.)
The short and long term pathophysiology of traumatic brain injury (TBI) has not been fully elucidated. Individuals recently suffering a mild TBI (mTBI) or having a history of TBI frequently suffer deficits in their ability to maintain and allocate attention within and between tasks. This dissertation examines the influence of mild and chronic TBI on performance of task switching. We employed spatial and numerical task switching paradigms to assess the behavioral deficits in mTBI, and we used an internally generated switching and an externally cued switching task along with functional Magnetic Resonance Imaging (fMRI) to assess the long term deficits in executive function resulting from chronic TBI.
In the first experiment, individuals with mTBI were identified and tested within the first 48 hours of injury and then at a set interval 5, 14, and 28 days post injury. In the second investigation, individuals with chronic TBI were tested at least 12 months after their most recent injury. Healthy gender, age, and education matched controls were also tested in both studies.
This research demonstrated that mTBI subjects display deficits in switching behavior within 48 hours of injury that failed to resolve a month post-injury; however, these costs did not generalize across the switching task types. Chronic TBI subjects performed internally generated and externally cued switching paradigms with a degree of success equivalent to that of healthy controls but displayed larger amounts of activation and recruited more areas of the brain at lower levels of difficulty and did not increase recruitment in a stepwise fashion at higher levels of difficulty.
Mild TBI causes significant deficits in task switching, but there is specificity in these deficits. Chronic TBI patients performed at a level equivalent to that of controls but displayed different patterns and degree of activation. Taken together, these findings indicate that there may be a specific time frame during which task switching shows behavioral deficits, after which the subject may compensate for these deficits to produce normalized performance.
Committee in Charge: Dr. Paul van Donkelaar, Chair;
Dr. Li-Shan Chou;
Dr. Ulrich Mayr;
Dr. Marjorie Woollacott
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, Ph. D., 2010;
Executive function
Traumatic brain injury
Neurosciences
Physiology
Brain injury
Brain -- Pathophysiology
Executive function deficits in traumatic brain injury
Thesis

Howell, David Robert, 1986-
2011-08-19T18:54:15Z
2011-08-19T18:54:15Z
2011-06
http://hdl.handle.net/1794/11492
xvi, 68 p. : ill.
Approximately 1.5 million concussions occur annually in the United States, many affecting individuals between the ages of 15 and 18. Little is known about this age group's response to a concussion as they have been thought to respond differently than adults due to immature brain development. Additionally, relying on symptoms alone to determine level of brain function may lead to early return back to sport participation. Through the use of 3 computerized tests, neuropsychological and attentional deficit recovery post concussion was assessed between 12 subjects with concussions and 12 controls up to 2 months after injury. Memory tasks and symptoms resolved within a week after injury. Executive function tests showed small group differences up to two months post injury, suggesting these types of tests may be a useful tool in the evaluation of concussion recovery and provide an objective measure in evaluation.
Committee in charge: Dr. Li-Shan Chou, Chair;
Dr. Lou Osternig, Member;
Dr. Sierra Dawson, Member;
Dr. Grace Golden, Member
en_US
University of Oregon
University of Oregon theses, Dept. of Human Physiology, M.S., 2011;
Neurosciences
Health care management
Attention
Cognitive testing
Concussion recovery
Executive function
High school athletes
Brain -- Concussion
Evaluation of Neuropsychological and Attentional Disturbances in Concussed High School Athletes
Thesis